Releasable locking mechanism for optical connector

ABSTRACT

A receptacle ( 20 ) detachably accommodating a connector plug ( 34 ) connected to optical fibers ( 32 ) is rotatably supported by a shaft ( 14 ) provided in an installation table ( 10 ). The receptacle ( 20 ) is biased by a leaf spring ( 16 ) for biasing opposite ends of the shaft ( 14 ) in one direction. A locking/unlocking mechanism for selectively locking or unlocking the receptacle ( 20 ) connected with the connector plug ( 34 ) relative to the installation table ( 10 ) and a locking mechanism fixing portion ( 12 ) includes a locking nib ( 30 Ra) of a lock releasing button ( 30 R), a locking nib ( 30 La) of a lock releasing button ( 30 L), locking nib receiving portions ( 12   na,    12   nb ) and a coil spring ( 31 ).

TECHNICAL FIELD

The present invention relates to a releasable locking mechanism for anoptical connector including connector plugs and receptacle.

BACKGROUND ART

Optical fibers used as a transmission path in an optical communicationsystem are connected to each other by optical connectors as disclosed inPatent Document Nos. 1 and 2. The optical connectors put into practiceare an MT (Mechanically Transferable) type optical connector asdisclosed in Patent Document No. 1, an MPO (Multi-fiber Push On) typeoptical connector as disclosed in Patent Document No. 2 or others, forexample.

The MT type optical connector includes, as main elements, a firstconnector plug connected to one group of optical fibers, a secondconnector plug connected to the other group of optical fibers and alocking mechanism for holding the first connector plug and the secondconnector plug, while positioning connection end surfaces of therespective optical fibers projected from end surfaces of ferrules of therespective connector plug to each other so that the connection endsurfaces are brought into contact or close to each other.

The locking mechanism is required to hold the first and second connectorplugs in a state wherein the connection end surfaces of the respectivegroup of optical fibers are brought into contact or close to each otherso that the transmission efficiency and the optical connectioncharacteristics are favorably maintained.

As a locking mechanism, for example, as shown in Patent Document No. 1,a clamp spring disposed while straddling over the first and secondconnector plugs connected each other as a whole is proposed. The clampspring is formed in a flat plate shape, having curved pressed portionsat positions corresponding to rubber boots of the first and secondconnector plugs at a predetermined distance therebetween. The pressedportions bias the rubber boots of the first and second connector plugsin the direction that come close to each other by the resilience of thepressed portions.

When the clamp spring is mounted on the first connector plug and thesecond connector plug connected to each other, the first connector plugand the second connector plugs are forcibly pushed into a gap betweenpressing portions of the clamp spring opposed to each other against theelastic force of the pressing portions. Thereby, the clamp spring biasesthe end portions of the first connector plug and the second connectorplug encircled by the rubber boots so that the ferrules of the firstconnector plug and the second connector plug opposed to each other movecloser to each other in an axial direction of the optical fibers.Accordingly, the first connector plug and the second connector plug arein a locked state while keeping the connection ends surfaces of therespective groups of optical fibers being brought into contact or closeto each other.

On the other hand, when the clamp spring is detached from the firstconnector plug and the second plug connected to each other, the clampspring is forcibly separated from the first connector plug and thesecond connector plug against the frictional force caused by the elasticforce of the respective pressed portions.

Patent Document No. 1: Japanese Patent Gazette No. 3566881

Patent Document No. 2: Japanese Patent Gazette No. 03432394

DISCLOSURE OF THE INVENTION

In a case wherein the locking mechanism is structured by theabove-mentioned clamp spring, if the optical fibers are pulled againstthe elastic force of the pressed portion of the clamp spring with a pullforce exceeding a predetermined value defined to be larger than thepressing force applied to the pressed portion, in the direction whereinthe first connector plug and the second connector plug are apart fromeach other for any reason, there may be a risk in that the connectionend surfaces of the respective group of optical fibers are apart fromeach other to result in the transmission loss and the deterioration ofthe optical connection characteristics. In such a case, it may bethought to thicken a sheet thickness of the pressed portion of the clampspring so that the pressure of the respective pressed portion becomeshigher than the predicted pulling force.

However, when the operator mounts/demounts the clamp spring to/from thefirst connector plug and the second connector plug to be connected tothe clamp spring, it is difficult for the operator to mount/demount theclamp spring while gripping the first connector plug and the secondconnector plug as well as the plate-like clamp spring by his or her bothhands, whereby this countermeasure is inadvisable.

By taking such a problem into consideration, the present invention aimsto provide a releasable locking mechanism for optical fibers includingconnector plugs and receptacle capable of avoiding the relative movementof the connector plugs and the connection end surfaces of the opticalfibers even if a pull force is applied to the group of optical fibers inthe axial direction thereof for any reason, whereby it is possible toprevent the connection end surfaces of the respective optical fibersfrom separating from each other as well as to easily operate the lockingmechanism.

To achieve the above-mentioned object, a releasable locking mechanismfor optical fibers according to the present invention comprises a lockreleasing button having a lock-fixing portion and movably disposed ineither one of a receptacle or a base disposed opposite to thereceptacle, the receptacle having a connector plug accommodation portionfor detachably accommodating a connector plug, the connector plug beingconnected to optical fibers to form a transmission path forphotoelectric converted signals, a locking nib receiving portion formedopposite to the lock releasing button in either one of said receptacleor said base, for selectively fixing the lock-fixing portion to resultin a locked state of the receptacle and the connector plug relative tothe base, a first biasing member for biasing a locking nib of the lockreleasing button in direction that fix it to the locking nib receivingportion, a position restricting surface for touching and holding an endof the connector plug mounted to said connector plug accommodationportion in the locked state, and a second biasing member for biasing thereceptacle in the axial direction of said optical fibers when an end ofthe connector plug mounted to the connector plug accommodation portionis retained by the position restricting surface.

Also, a releasable locking mechanism for an optical connector accordingto the present invention comprises a lock releasing button having alock-fixing portion and movably disposed in either one of a receptacleor a base disposed opposite to the receptacle the receptacle having aconnector plug accommodation portion for detachably accommodating aconnector plug being connected to optical fibers to form a transmissionpath for photoelectric converted signals, a locking nib receivingportion formed opposite to the lock releasing button in either one ofsaid receptacle or said base, for selectively fixing the lock-fixingportion to result in a locked state of said receptacle and the connectorplug relative to the base, a first biasing member for biasing a lockingnib of the lock releasing button in direction that fix it to the lockingnib receiving portion, a position restricting member disposed in thebase, for restricting the position of a predetermined end of theconnector plug mounted to the connector plug accommodation portion whenthe connector plug is in the locked state, and a second biasing memberfor biasing ends of the connector plug and the optical fibers toward thebottom of the connector plug accommodation portion in the axialdirection of the optical fibers when the position of the end of theconnector plug is restricted by the position restricting member.

As apparent for the above description, in the releasable lockingmechanism for the optical connector according to the present invention,since the second biasing member biases the receptacle in the axialdirection of the optical fibers when the end of the connector plugmounted to the connector plug accommodation portion is held by theposition restricting surface, the mutual displacement of the connectorplug and the connecting end surface of the optical fiber is inhibitedeven if a stretching force is applied to the optical fibers in the axialdirection thereof by any cause, whereby the separation of the connectingends of the respective optical fibers is avoidable. Further, it ispossible to easily operate the locking mechanism by the movement of thelock releasing button.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view illustrating an appearance of an opticalconnector provided with a first embodiment of a releasable lockingmechanism for an optical connector according to the present invention;

FIG. 2 is a perspective view illustrating a locked state of a receptaclemounting a connector plug in the embodiment shown in FIG. 1;

FIG. 3 is an exploded perspective view of the embodiment shown in FIG.1;

FIG. 4 is a perspective view of the receptacle in an unlocked state inthe embodiment shown in FIG. 1;

FIG. 5 is an enlarged partial sectional view of part of a receptacle anda connector plug in an embodiment shown in FIG. 2;

FIG. 6A is a perspective view made available for illustrating theoperation of the embodiment shown in FIG. 1;

FIG. 6B is a perspective view made available for illustrating theoperation of the embodiment shown in FIG. 1;

FIG. 6C is a perspective view made available for illustrating theoperation of the embodiment shown in FIG. 1;

FIG. 7A is a partially sectional view made available for illustratingthe operation of the embodiment shown in FIG. 1;

FIG. 7B is a partially sectional view made available for illustratingthe operation of the embodiment shown in FIG. 1;

FIG. 7C is a partially sectional view made available for illustratingthe operation of the embodiment shown in FIG. 1;

FIG. 7D is a partially sectional view made available for illustratingthe operation of the embodiment shown in FIG. 1;

FIG. 7E is a partially sectional view made available for illustratingthe operation of the embodiment shown in FIG. 1;

FIG. 8A is a view made available for illustrating the operation of theembodiment shown in FIG. 1;

FIG. 8B is a view made available for illustrating the operation of theembodiment shown in FIG. 1;

FIG. 8C is a view made available for illustrating the operation of theembodiment shown in FIG. 1;

FIG. 9A is a view made available for illustrating the operation of theembodiment shown in FIG. 1;

FIG. 9B is a partially side view made available for illustrating theoperation of the embodiment shown in FIG. 1;

FIG. 9C is a partially side view made available for illustrating theoperation of the embodiment shown in FIG. 1;

FIG. 9D is a partially side view made available for illustrating theoperation of the embodiment shown in FIG. 1;

FIG. 10A is a view made available for illustrating the operation of theembodiment shown in FIG. 1;

FIG. 10B is a view made available for illustrating the operation of theembodiment shown in FIG. 1;

FIG. 10C is a view made available for illustrating the operation of theembodiment shown in FIG. 1;

FIG. 10D is a view made available for illustrating the operation of theembodiment shown in FIG. 1;

FIG. 11A is a perspective view made available for illustrating theoperation of the embodiment shown in FIG. 1;

FIG. 11B is a perspective view made available for illustrating theoperation of the embodiment shown in FIG. 1;

FIG. 12 is an exploded perspective view illustrating an opticalconnector provided with a second embodiment of a releasable lockingmechanism for an optical connector according to the present invention;

FIG. 13 is a perspective view of the embodiment shown in FIG. 12 fromwhich is demounted a receptacle;

FIG. 14 is a perspective view of the embodiment shown in FIG. 12 towhich is mounted a receptacle;

FIG. 15 is a perspective view of the embodiment shown in FIG. 12 whereinthe receptacle is in a locked state;

FIG. 16A is a view made available for illustrating the operation of theembodiment shown in FIG. 12;

FIG. 16B is a view made available for illustrating the operation of theembodiment shown in FIG. 12;

FIG. 16C is a view made available for illustrating the operation of theembodiment shown in FIG. 12;

FIG. 17 is a perspective view illustrating a third embodiment of areleasable locking mechanism for an optical connector according to thepresent invention;

FIG. 18 is a perspective view of the embodiment shown in FIG. 17;

FIG. 19 is an exploded perspective view of constituent elements of theembodiment shown in FIG. 17;

FIG. 20A is a view made available for illustrating the operation of theembodiment shown in FIG. 17;

FIG. 20B is a view made available for illustrating the operation of theembodiment shown in FIG. 17;

FIG. 20C is a view made available for illustrating the operation of theembodiment shown in FIG. 17;

FIG. 20D is a view made available for illustrating the operation of theembodiment shown in FIG. 17;

FIG. 21 is a perspective view illustrating a fourth embodiment of areleasable locking mechanism for an optical connector according to thepresent invention;

FIG. 22 is a perspective view of the embodiment shown in FIG. 21; and

FIG. 23 is an exploded perspective view of constituent elements of theembodiment shown in FIG. 21.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 2 illustrates an appearance of an optical connector provided with afirst embodiment of a releasable locking mechanism according to thepresent invention.

In FIG. 2, the optical connector is arranged on a printed wiring boardconstituting part of an optical communication system, for example.

The optical connector includes, as main elements, a installation table10 disposed on the printed wiring board, a connector plug 34 connectedto one end of a group of optical fibers 32, and a receptacle 20rotational movable supported by the installation table 10, fordetachably accommodating a tubular portion (see FIG. 5) as a connectingsection of the connector plug 34. In addition thereto, the opticalconnector further includes a locking/unlocking mechanism for locking orunlocking the connector plug 34 relative to the receptacle 20 and awiring unit section for electrically connecting the printed wiring boardnot illustrated to the receptacle 20 described later.

Also, in the wiring unit section, as shown in FIG. 1 as a chaindouble-dashed line, a metallic heat sink 13 may be provided adjacent tothe installation table 10, as means for effectively dissipating heatgenerating in relation to the printed wiring board or the receptacle 20.

In this regard, FIG. 2 illustrates a state wherein the connector plug 34is locked to the receptacle 20 and the installation table 10.

Kinds of optical fibers 32 are, for example, a single mode or a multimode. Also, the optical fibers 32 are a bundle of individual wireshaving a predetermined diameter. In this regard, the optical fibers 32may be a tape type core wire, for example.

As shown in FIG. 3, the installation table 10 made, for example, ofresin has a pair of bearings 10EL and 10ER at on end thereof. The pairof bearings 10EL and 10ER are opposed to each other at predetermineddistance between the both. As shown in FIG. 4, coupling portions 20B and20C of the receptacle 20 described later are arranged between thebearings 10EL and 10ER.

The bearing 10ER has a slit 10S1 at a middle portion thereof, formedparallel to a side surface of the installation table 10. Also,ellipsoidal holes 10 a and 10 b are formed in the bearing 10ER on acommon central axis. Into the respective holes 10 a and 10 b, one end ofa columnar shaft 14 are inserted via reinforcement sleeves 15 whilecrossing the slits 10S1. In this regard, the holes 10 a and 10 b havethe same shape to each other, and a length of a major axis of each theholes 10 a and 10 b is determined in accordance with a moving amount ofone end of the shaft 14 described later and an elastic displacement of amovable end of a leaf spring 16

In FIG. 3, circular holes 10 f and 10 g are formed on a common centralaxis at positions obliquely lower left relative to the above-mentionedcircular holes 10 a and 10 b. Into the holes 10 f and 10 g, oppositeends of a shaft 18 described later are inserted while crossing the slit10S1. The shaft 18 that is a so-called stopper pin for fixing the leafspring 16 has a diameter smaller than that of the shaft 14.

In the slit 10S1, there are one end of the shaft 14, a reinforcementsleeve 15 and a plurality of leaf springs 16 as a second biasing memberdescribed later.

At each of opposite ends of the shaft 14, the reinforcement sleeve 15 ispress-fit. An outer diameter of the mounted reinforcement sleeve 15 isdetermined so that a predetermined gap is formed around the innercircumference of the holes 10 a and 10 b. A total length of the shaft 14is approximately equal to a length of a short side of the installationtable 10.

The leaf spring 16 as a second biasing member is formed, for example, ofa stamped thin steel sheet to have a roughly ohm (Ω) shape constitutedby a fixed end portion 16A and a movable end portion 16B, each having anelongate hole 16 a and a circular hole 16 b, as well as an elastic bendportion 16C coupling the fixed end portion 16A and the movable endportion 16B to each other. The reinforcement sleeve 15 and the one endof the shaft 14 pass through the hole 16 b larger than the elongate hole16 a. On the other hand, a shaft 18 passes through the elongate hole 16a. Note the leaf spring 16 used as an elastic member should not belimited to this example but may be formed of heat-resistant rubber orothers.

As shown in FIGS. 10B and 10C, the movable end portion 16B is movable bythe bend portion 16C away from or move closer to the fixed end portion16A at a predetermined displacement in accordance with the movement ofthe shaft 14.

In this regard, while the a plurality of leaf springs 16 formed of thinsheets is used in this embodiment, this is not limitative but a leafspring formed of a single sheet having the same thickness as a totalthicknesses of the plurality of thin sheets may be disposed in the slit10S1. Also, while the movable end portion 16B of the leaf spring 16 isfit to the outer periphery of the shaft 14, this is not limitative but arecess or a curvature portion formed in the movable end portion of theleaf spring 16 as an elastic member may be directly or indirectly via aninterposed member engaged with the outer periphery of the shaft 14 notto be unfastened.

The bearing 10EL has a slit 10S2 at a middle portion thereof, formedparallel to the side surface of the installation table 10. Also, in thebearing 10EL, ellipsoidal holes 10 d and 10 e are formed on a commonaxis. Into the holes 10 d and 10 e, the other end of the above-mentionedshaft 14 is inserted via a reinforcement sleeve 15 while crossing theslit 10S2. In this regard, the ellipsoidal holes 10 d and 10 e opposedto the above-mentioned holes 10 a and 10 b have the same shape, and alength of a major axis of the ellipsoidal holes 10 d and 10 e aredetermined in accordance with the moving amount of one end of theabove-mentioned shaft 14 as well as the elastic displacement of themovable end portion of the leaf spring 16.

Also, in FIG. 3, at positions obliquely lower left relative to theabove-mentioned circular holes 10 d and 10 e, circular holes 10 h and 10i are formed on a common central axis, into which are inserted oppositeends of the above-mentioned shaft 18 while crossing the slit 10S2. Inthe slit 10S2, similar to the slit 10S1, the other end of theabove-mentioned shaft 14, reinforcement sleeve 15 and theabove-mentioned plurality of leaf springs 16 as a second biasing memberare provided.

There is fixed a locking mechanism fixing portion 12 consisting of alocking mechanism fixing walls 12WR and 12WL at an end of theinstallation table 10 opposed to the receptacle 20. In this regard,while the locking mechanism fixing portion 12 is formed separately fromthe installation table 10 according to this embodiment, this is notlimitative, but for example, the locking mechanism fixing portion 12 maybe formed in integral with the installation table 10 as a so-calledbase.

As shown in FIG. 3, the locking mechanism fixing wall 12WR and thelocking mechanism fixing wall 12WL are formed opposite to one anotheracross a communication path 12A.

On a wall surface of the locking mechanism fixing wall 12WR opposed tothe communication path 12A, a recess 12 wd is formed. In the recess 12wd, as shown in FIG. 2, a projection provided at a rear end of theconnector plug 34 described later is inserted at a predetermined gapwhen the connector plug 34 is connected. Also, on an end surface 12 wbof the locking mechanism fixing wall 12WR opposed to the receptacle 20,a recess 12 we is formed. On a wall surface forming the recess 12 we, alocking nib receiving portion 12 nb is formed as part of a lockingmechanism/unlocking mechanism described later. For example, thehook-shaped locking nib receiving portion 12 nb is formedperpendicularly to a side surface of the locking mechanism fixing wall12WR to be projected into the recess 12 we. In the upper part of thelocking nib receiving portion 12 nb, as shown in FIGS. 3 and 7A to 7E, aslant 12 ns for guiding a locking nib of the receptacle 20 describedlater is formed. A retaining surface formed in a lower part of thelocking nib receiving portion 12 nb contiguous to the slant 12 ns isformed generally perpendicular to the side surface of the lockingmechanism fixing wall 12WR.

On a wall surface of the locking mechanism fixing wall 12WL opposed tothe communication path 12A, a recess 12 wc is formed. In the recess 12wc, as shown in FIG. 2, a projection opposed to the projection providedat the rear end of the connector plug 34 described above is inserted ata predetermined gap when the connector plug 34 is connected. Also, on anend surface 12 wa of the locking mechanism fixing wall 12WL opposed tothe receptacle 20 as a position-restriction surface, a recess 12 we isformed. On a wall surface forming the recess 12 we, a locking nibreceiving portion 12 na is comprised as part of the lockingmechanism/unlocking mechanism described later. The locking nib receivingportion 12 na is formed perpendicularly to a side surface of the lockingmechanism fixing wall 12WL to be projected into the recess 12 we. In theupper part of the locking nib receiving portion 12 na, as shown in FIGS.3 and 7A to 7E, a slant 12 ns for guiding a locking nib of thereceptacle 20 described later is formed. A retaining surface formed in alower part of the locking nib receiving portion 12 na contiguous to theslant 12 ns is formed generally perpendicular to the side surface of thelocking mechanism fixing wall 12WL.

As shown in FIG. 7E, on a bottom of the communication path 12A, grooves12 ga and 12 gb are formed generally parallel to each other, into whichare inserted projections 34 pb, respectively, opposed to a pair ofprojections 34 pa of the connector plug 34. Depths of the grooves 12 gaand 12 gb are of the same dimension capable of completely accommodatingthe projections 34 pb.

As shown in FIGS. 4 and 5, the receptacle 20 mainly includes a rotatablebase 20F having coupling portions 20B and 20C coupled to a middleportion of the above-mentioned shaft 14 and an end cap 20E covering oneend of the rotatable base 20F.

As shown in FIGS. 3 and 5, the coupling portions 20B and 20C formed on alower surface of the rotatable base 20F opposite to each other at apredetermined distance have holes 20 b and 20 d, respectively, throughwhich is inserted the middle portion of the shaft 14. Thereby, thereceptacle 20 is supported by the rotatable base 20F and the shaft 14 tobe rotatable relative to the installation base 10.

As shown in FIG. 4, the rotatable base 20F has a connector plugaccommodation portion 20A for removably accommodating a tubular portion34CL of the connector plug 34 as a connecting portion. In the interiorof the connector plug accommodation portion 20A, a guide member 35 forguiding and supporting the tubular portion 34CL of the mounted connectorplug is formed as enlarged in FIG. 5. Accordingly, the tubular portion34CL of the connector plug 34 could be easily mounted to the connectorplug accommodation portion 20A with a relatively small operative force.

On the inner circumference of the guide member 35, a micro-hole 35 a isformed, through which a wire of optical fibers 32 projected into thetubular portion 34CL of the connector plug 34 passes. On the boundarybetween the connector plug accommodation portion and an end cap 20Edescribed later, there is a transparent thin plate member 22 providedwith a micro-lens 22L to which touches an end surface of the wire of theoptical fibers 32 projected via the micro-hole 35 a at a predeterminedpressure. The thin plate member 22 may be made of glass or transparentresin. The thin plate member 22 is joined to an end of the connectorplug accommodation portion 20A by the outer peripheral edge thereof.Also, since a center of an optical axis of the micro-lens 22L coincideswith a center of an inner diameter of the micro-hole, it is possible tocollimate light output from the optical fiber 32 or joint the collimatedlight to the optical fiber 32, whereby the input/output of outsideoptical signals becomes easy.

A vertical-cavity surface-emitting optical semiconductor element 24 isprovided opposite to the above-mentioned micro-lens 22L on the inside ofthe end cap 20E. The vertical-cavity surface-emitting opticalsemiconductor element 24 is connected to a wiring portion 26 which inturn is electrically connected to the above-mentioned wiring unitsection. Thereby, the vertical-cavity surface-emitting opticalsemiconductor element 24 is electrically connected to theabove-mentioned printed wiring board via the wiring unit and the wiringportion 26.

At positions on the opposite sides of the connector plug accommodationportion 20A, as shown in FIG. 4, button accommodation portions 20RR and20RL are formed, for movably accommodating lock releasing buttons 30Rand 30L.

At an end of a wall forming the button accommodation portion 20RR,opposed to the locking mechanism fixing wall 12WR, and on a sidevertical to that end, as shown in FIG. 4, an opening is formed wherein alocking nib 30Ra of the lock releasing button 30R and an operating partthereof project, respectively. Also, at an end of a wall forming thebutton accommodation portion 20RL, opposed to the locking mechanismfixing wall 12WL, and on a side vertical to that end, as shown in FIG.4, an opening is formed wherein a locking nib 30La of the lock releasingbutton 30L and an operating part thereof project, respectively.

The lock releasing button 30R is disposed in the button accommodationportion 20RR along an axis of the shaft 14, that is, to be reciprocablegenerally perpendicular to a long side of the installation table 10. Asshown in FIG. 7A, coil springs 31 are disposed as a first biasing memberfor biasing the lock releasing button 30R between ends of the lockreleasing button 30R and the inner periphery of the button accommodationportion 20RR. The lock releasing button 30R has a step for engaging itsoperating part with a periphery of the opening. By the engagement of astep disposed within the button accommodation portion 20RR with theperiphery of the opening, the release of the lock releasing button 30Ras well as the predetermined amount of the movement thereof arerestricted.

As shown in FIG. 1, a slant 30Rs of the generally triangular locking nib30Ra of the lock releasing button 30R is formed opposite to a slant 12ns of the above-mentioned locking nib receiving portion 12 nb. Also, onone of two sides intersecting the slant 30Rs, an engagement surface 30Rtis formed for engaging with a retaining surface contiguous to the slant12 ns of the locking nib receiving portion 12 nb, when the receptacle 20is made to rotate in the direction indicated by an arrow L in FIG. 4 tobe in a locked state as described later.

The lock releasing button 30L is disposed in the button accommodationportion 20RL to be reciprocable along the axis of the shaft 14, i.e.,generally vertical to the long side of the installation table 10. Asshown in FIG. 7A, between ends of the lock releasing button 30L and theinner periphery of the button accommodation portion 20RL, coil springs31 for biasing the lock releasing button 30L are provided. The lockreleasing button 30L has a step for engaging its operating part with aperiphery of the opening. By the engagement of a step disposed withinthe button accommodation portion 20RL with the periphery of the opening,the release of the lock releasing button 30L as well as thepredetermined amount of the movement thereof are restricted.

As shown in FIG. 1, a slant 30Ls of the generally triangular locking nib30La of the lock releasing button 30L is formed opposite to a slant 12ns of the above-mentioned locking nib receiving portion 12 na. Also, asshown in FIG. 7E, on one of two sides intersecting the slant 30Ls, anengagement surface 30Lt is formed for engaging with a retaining surfacecontiguous to the slant 12 ns of the locking nib receiving portion 12na, when the receptacle 20 is made to rotate in the direction indicatedby an arrow L in FIG. 4 to be in a locked state as described later.

Accordingly, the locking/unlocking mechanism for locating the receptacle20 connected to the connector plug 34 selectively in the locked state orthe unlocked state relative to the installation table 10 and the lockingmechanism fixing portion 12 includes the locking nib 30Ra of the lockreleasing button 30R and the locking nib 30La of the lock releasingbutton 30L; locking nib receiving portions 12 na and 12 nb; and the coilsprings 31.

In such a structure, as shown in FIGS. 8A and 8B, when the receptacle 20to which is mounted the connector plug 34 is in the locked staterelative to the locking mechanism fixing portion 12, the receptacle 20is first made to rotate against the biasing force of the leaf spring 16toward the end surfaces 12 wa and 12 wb of the locking mechanism fixingportion 12 as shown in FIGS. 7A and 8C.

Then, as shown in FIGS. 7B and 7C, when the receptacle 20 is furthermade to rotate, the slants 30Rs and 30Ls of the locking nib 30Ra slideon the slants 12 ns of the locking nib receiving portions 12 na and 12nb, whereby the locking nib 30Ra and the locking nib 30La are moved inthe direction to move closer to each other against the biasing force ofthe coil spring 31.

Subsequently, when the locking nib 30Ra and the locking nib 30La aremoved to a predetermined maximum displacement by further pushing androtating the receptacle 20, the slants 30Rs and 30Ls of the locking nib30Ra and the locking nib 30La are pressed down while being apart fromthe end of the slant 12 ns, as shown in FIG. 7D. Thereby, the lockingnib 30Ra and the locking nib 30La are respectively displaced apart fromeach other by the biasing force of the coil spring 31, and thus, asshown in FIG. 7E, the engagement surfaces 30Rt and 30Lt of the lockingnib 30Ra and the locking nib 30La are engaged with the retainingsurfaces of the locking nib receiving portions 12 na and 12 nb,respectively, to be a locking state. At that time, since two projections34 pb of the connector plug 34 are inserted into the groove 12 ga andthe groove 12 gb, respectively, an outer surface of the connector plug34 touches to the bottom surface of the communication path 12A.

Accordingly, the movement of the receptacle 20 to which is mounted theconnector plug 34 is restricted in either of directions on thecoordinate axes X, Y and Z of a rectangular coordinates shown in FIG.7E. Note that the coordinate axis Z is defined along the axial directionof the connector plug 34 and the optical fibers 32.

On the other hand, when the receptacle 20 to which is mounted theconnector plug 34 is changed from the locked state to the unlocked staterelative to the locking mechanism fixing portion 12, as shown in FIG.6A, first the operating part of the lock releasing button 30R and theoperating part of the lock releasing button 30L are pressed against thebiasing force of the coil spring 31 in the direction shown by an arrow;i.e., move closer to each other. Thereby, the engagement surfaces 30Rtand 30Lt of the locking nib 12 na and the locking nib 12 nb are in thenon-engagement state with the retaining surfaces of the locking nibreceiving portions 12 na and 12 nb; i.e., in the unlocked state.

Next, as shown in FIG. 6B, in a state wherein the operating part of thelocking releasing button 30R and the operating part of the lockingreleasing button 30L are pressed and held, the receptacle 20 is made torotate counterclockwise at a predetermined angle in FIG. 6B. At thattime, as shown in FIG. 6C, the operating part of the lock releasingbutton 30R and the operating part of the lock releasing button 30Lreturn to the initial state by the biasing force of the coil spring 31.

And, the receptacle 20 to which is mounted the connector plug 34 returnsto its initial position by the biasing force of the leaf spring 16.

Accordingly, the attachment/detachment of the connector plug 34 relativeto the receptacle 20 could be carried out regardless of the rotatingposition of the receptacle 20, for example, the vertical position or theoblique position, and, in addition thereto, the handling of theconnector plug 34 becomes easy.

As described above, when the receptacle 20 to which is mounted theconnector plug 34 is in a locked state relative to the locking mechanismfixing portion 12, the end of the shaft 14 is positioned at one end ofthe hole 10 a at an initial position as shown in FIGS. 9A and 10A, andthe movable end 16B of the leaf spring 16 does not yet commence itsmovement.

Next, when the receptacle 20 is further rotates against the biasingforce of the leaf spring 16 as shown in FIGS. 9B and 10B, a pair ofprojections 34 eb and 34 ea formed opposite to the outer periphery ofthe connector plug 34 touch to the end surfaces 12 wb and 12 wa of thelocking mechanism fixing portion 12 as enlarged in FIG. 11A.

Subsequently, when the receptacle 20 is further pressed and made torotate against the biasing force of the leaf spring 16, the projections34 eb and 34 ea are moved downward while sliding on the end surface 12wb and 12 wa of the locking mechanism fixing portion 12 as shown inFIGS. 9C and 10C. At that time, as shown in FIGS. 9C and 10C, since thecoupling portions 20B, 20C of the receptacle 20 and the connector plug34 are pressed against the biasing force of the leaf spring 16, theshaft 14 is moved away from one end of the hole 10 a toward the otherend. Also, the movable end 16B of the leaf spring 16 is moved in thedirection indicated by an arrow in FIG. 10C.

As shown in FIGS. 9D and 10D, in the state described above wherein thereceptacle 20 is locked relative to the locking mechanism fixing portion12, the shaft 14 touches to the other end of the hole 10 a against thebiasing force of the leaf spring 16. Also, as enlarged in FIG. 11B, thepair of projections 34 eb and 34 ea touch to the end surfaces 12 wb and12 wa of the locking mechanism fixing portion 12, respectively, and, inaddition thereto, the connector plug 34 is pressed in a more stablestate in the direction indicating by an arrow in FIG. 10D via thereceptacle 20 by the biasing force of the leaf spring 16. At that time,since the pair of projections 34 eb and 34 ea pressed by the biasingforce of the leaf spring 16 touch to the end surface 12 wb and 12 wa ofthe locking mechanism fixing portion 12, the optical fibers 32 areimmobile at all even if any stretching force is applied thereto, wherebythe inconvenience is avoidable, wherein a gap of about 50 μm isgenerated between the micro-lens 22L and an end surface of a front endof the connector plug, and a front end of a wire of the optical fiber 32is not brought into close contact with the micro-lens 22L, resulting inthe impossibility of optical transmission.

The micro-lens 22L of the receptacle 20 is pressed to a contact end ofthe wire of the optical fibers 32 in the connecting portion of theconnector plug 34 by a reactive force corresponding to the displacementamount of the movable end of the leaf spring 16, whereby a predeterminedaxial force operates in the direction indicated by an arrow in FIG. 5.For example, it is necessary to apply an axial force of about 50 g to asingle wire of one optical fiber 32 and maintains the same. If theoptical fibers 32 are formed of a number of wires, for example, 20wires, the axial force of 50 g×20 wires=1000 g=1 kg is necessary.

FIG. 14 illustrates part of the appearance of an optical connectorprovided with a releasable locking mechanism according to a secondembodiment of the present invention.

In this regard, in FIGS. 12 to 16A, 16B and 16C described later as wellas in further embodiments described later, the same reference numeralswill be used for denoting the same constituent elements as those in thefirst embodiment shown in FIG. 2 and the redundant description thereofwill be eliminated.

In FIG. 14, the optical connector is disposed on a printed wiring boardconstituting, for example, part of an optical communication system.

The optical connector mainly includes an installation table 40 disposedon the printed wiring board (not illustrated), a connector plug 34 (seeFIGS. 16A, 16B and 16C) connected to one end of a group of opticalfibers 32, and a receptacle 20 rotatably held on the installation table40, for detachably accommodating a tubular portion (see FIG. 5) as aconnecting section of the connector plug 34. Also, in addition thereto,the optical connector also has a locking/unlocking mechanism for makingthe connector plug 34 to be in the locked state or the unlocked staterelative to the receptacle 20, and a wiring unit section forelectrically connecting the printed wiring board not shown with thereceptacle 20 described later. In the wiring unit section, as shown inFIG. 14 by a chain double-dashed line, a metallic heat sink 13 may beprovided adjacent to the installation table 40, as means for effectivelydissipating heat generated in relation to the printed wiring board orthe receptacle 20.

For example, at one end of the installation table 40 made of resin, apair of bearings 40EL and 40ER are formed opposite to each other at apredetermined interval. Between the bearings 40EL and 40ER, couplingportions 20B and 20C of the receptacle 20 are arranged, as illustratedin FIGS. 14 and 15.

In the bearings 40ER and 40EL, there are circular holes 40 a and 40 b ona common central axis into which is inserted opposite ends of a shaft 14via reinforcement sleeves 15, respectively. A total length of the shaft14 is approximately equal to a length of a short side of theinstallation table 40.

At an end of the installation table 40 opposed to the receptacle 20, alocking mechanism fixing portion 42 including locking mechanism fixingwalls 42WR and 42WL is fixed.

The locking mechanism fixing wall 42WR and the locking mechanism fixingwall 42WL are formed opposite to each other across a communication path42A as shown in FIG. 12.

On an end surface of the locking mechanism fixing wall 42WR opposed tothe receptacle 20, a recess 42 we is formed. On a wall surface formingthe recess 42 we, there is formed a locking nib receiving portion 42 nbconstituting part of the locking mechanism described later. The lockingnib receiving portion 42 nb is perpendicular to a side surface of thelocking mechanism fixing wall 42WR and projects toward the communicationpath 42A. In an upper part of the locking nib receiving portion 42 nb, aslant 42 ns for guiding the locking nib of the receptacle 20 is formedsimilarly to the first embodiment. A retaining surface formed on a lowerpart of the locking nib receiving portion 42 nb contiguous to the slant42 ns is generally perpendicular to a side surface of the lockingmechanism fixing wall 42WR.

On an end surface of the locking mechanism fixing wall 42WL opposed tothe receptacle 20 a recess 42 wd is formed. On the wall surface formingthe recess 42 wd, a locking nib receiving portion 42 na constitutingpart of the locking mechanism described later is formed. The locking nibreceiving portion 42 na is formed perpendicular to the side surface ofthe locking mechanism fixing wall 42WL while projecting toward thecommunication path 42A. In an upper part of the locking nib receivingportion 42 na, a slant 42 ns for guiding the locking nib of thereceptacle 20 is formed opposite to the slant 42 ns of the locking nibreceiving portion 42 nb. A retaining surface formed in a lower part ofthe locking nib receiving portion 42 na is formed generallyperpendicular to a side surface of the locking mechanism fixing wall42WL.

On the bottom of the communication path 42A, grooves 42 ga and 42 gbinto which are inserted projections 34 pb of the connector plug 34 areformed generally parallel to each other as illustrated in FIGS. 12 and13. Depths of the grooves 42 ga and 42 gb are of the same dimensioncapable of completely accommodating the projections 34 pb.

An open end formed at one ends of the grooves 42 ga and 42 gb projectsfrom ends of other portions on the bottom of the communication path 42Aby a predetermined length. By the intersection of the projected openends of the grooves 42 ga and 42 gb with the ends of the other portionson the bottom of the communication path 42A, a stopper portion 42 s tobe locked with a position-restriction part of a position-restrictionmember 48 is formed. Accordingly, a step is formed between the bottom ofthe communication path 42A on which is formed the stopper 42 s and aportion in which are formed the grooves 42 a and 42 gb.

Further, two holes 42 d into which are press-fit two shaft portions 44 aof a spring presser 44 described later are formed between the innerperiphery of the locking mechanism fixing wall 42WR and the groove 42ga, and between the inner periphery of the locking mechanism fixing wall42WL and the groove 42 gb, respectively.

As shown in FIGS. 13 and 14, in the communication path 42A, a leafspring 46 is disposed, for biasing an end portion 34EE of the connectorplug 34 toward the receptacle 20. The leaf spring 46 as a second biasingmember comprises a gate type fixing portion and pressing pieces 46A and46B formed integral with the fixing portion, the pressing pieces beingin contact with and pressing the end portion 34EE of the connector plug34 as shown in FIG. 12. On opposite sides of the fixing portion, twoholes 46 a, 46 b into which are inserted two shaft portions 44 a of therespective spring presser 44 are formed. Thereby, as shown in FIGS. 13and 14, the two shaft portions 44 a of the respective spring presser 44are press-fit into the holes 42 d via the holes 46 a, 46 b to fix theleaf spring 46 to the bottom of the communication path 42A.

Proximal ends of the pressing pieces 46A and 46B are integral with thefixing portion at a predetermined interval. The other end of thepressing piece 46A, 46B is inclined and curved toward the end portion34EE of the connector plug 34 as shown in FIG. 16A.

Further, in an portion of the installation table 40 wherein thereceptacle 20 communicated to the communication path is disposed, aposition restricting member 48 is arranged at a position beneath thereceptacle 20, for restricting the displacement of the connector plug 34when the receptacle 20 is locked relative to the locking mechanismfixing portion 42.

The position restricting member 48 is made of flat plate to have a frameshape including, as shown in FIG. 12, a curvature portion forming a pairof bearings 48 a and 48 b engageable with a middle portion of the shaft14, and a bending portion having a pair of fixing pieces 48S1 and 48S2as position restricting means opposite to the curvature portion. Asillustrated in FIG. 13, the bearings 48Ba and 48Bb of the curvatureportion have arcuate parts corresponding to outer periphery of themiddle portion of the shaft 14, respectively, formed by partiallycutting out so that the middle portion of the shaft 14 can be inserted.The fixing pieces 48S1 and 48S2 are formed generally parallel to eachother away from each other at a predetermined distance to be fixed withthe stopper portion 42 s at the open end of the above-mentionedprojected grooves 42 ga and 42 gb. The fixing pieces 48S1 and 48S2 areformed while generally perpendicularly extending relative to the bottomsurface of the communication path 42A. Accordingly, theposition-restriction member 48 is positioned by the engagement of thebearings 48Ba and 48Bb of the curvature portion thereof with the middleportion of the shaft 14, and fixed to the installation table 40 by thefixing of the fixing pieces 48S1 and 48S2 with the stopper portion 42 s.Since the receptacle 20 is supported by the shaft 14 at that time, theconnector plug 34 is positioned to the receptacle 20 at a high accuracy.

In such a structure, when the receptacle 20 to which is mounted theconnector plug 34, is in a locked state relative to the lockingmechanism fixing portion 42, first, the receptacle 20 is made to rotatetoward the end surface of the locking mechanism fixing portion 42.

Then, when the receptacle 20 is further made to rotate, the slants 30Rsand 30Ls of the locking nib 30Ra slide, respectively, on the slants 42ns of the locking nib receiving portions 42 na and 42 nb, whereby thelocking nib s 30Ra and the locking nib s 30La are moved in the directioncoming closer to each other against the biasing force of the coil spring31.

Subsequently, when the receptacle 20 is further pressed and rotatedwhereby the locking nib 30Ra and the locking nib 30La are moved to apredetermined maximum displacement, the slants 30Rs and 30Ls of thelocking nib 30Ra and the locking nib 30La, respectively, are away fromthe ends of the slants 42 ns and pressed downward. Thereby, the lockingnib 30Ra and the locking nib 30La are moved away from each other,whereby the engagement surfaces 30Rt and 30Lt of the locking nib 30Raand the locking nib 30La are engaged with the retaining surfaces of thelocking nib receiving portions 42 na and 42 nb, respectively, resultingin the locked state. At that time, since the two projections 34 pb ofthe connector plug 34 are inserted into the grooves 12 ga and 12 gb, theouter surface of the connector plug 34 touches to the bottom surface ofthe communication path 42A.

Accordingly, similarly to the first embodiment, the movement of thereceptacle 20 mounted with the connector plug 34 is restricted in eitherof the directions on the coordinate axes X, Y and Z in the rectangularcoordinates shown in FIG. 7E.

On the other hand, when the receptacle 20 mounted with the connectorplug 34 is changed from the locked state to the unlocked state relativeto the locking mechanism fixing portion 42, the operating part of thelock releasing buttons 30R and the operating part of the lock releasingbutton 30L are first pressed against the biasing force of the coilspring 31 in the direction indicated by an arrow; i.e., move closer toeach other. Thereby, the engagement surfaces 30Rt and 30Lt of thelocking nib 30Ra and the locking nib 30La, respectively, become thenon-engagement state relative to the retaining surfaces of the lockingnib receiving portion potions 42 na and 42 nb, resulting in the unlockedstate.

Then, the receptacle 20 is made to rotate counterclockwise in FIG. 6B ata predetermined angle similarly to the first embodiment, whilemaintaining the operating part of the lock releasing button 30R and theoperating part of the lock releasing button 30L in the pressed state. Atthat time, the operating part of the lock releasing button 30R and theoperating part of the lock releasing button 30L return to the initialstate by the biasing force of the coil spring 31.

And, the receptacle 20 mounted with the connector plug 34 is detachedagainst the biasing force of the pressing pieces 46A and 46B.

As describe above, when the receptacle 20 mounted with the connectorplug 34 becomes the locked state relative to the locking mechanismfixing portion 42, during the rotation of the receptacle 20 from theinitial position shown in FIG. 16A to a position shown in FIG. 16B, theend portion 34EE of the connector plug 34 first touches to the pressingpieces 46A and 46B.

Then, as illustrated in FIG. 16C, when the end portion 34EE of theconnector plug 34 is further made to rotate against the elastic force ofthe pressing pieces 46A and 46B while sliding on the pressing pieces 46Aand 46B, a pair of projections 34 eb and 34 ea formed opposed to theouter periphery of the connector plug 34 touch to ends of the fixingpieces 48S1 and 48S2.

As shown in FIG. 16C, when the receptacle 20 is in the above-mentionedlocked state relative to the locking mechanism fixing portion 42, thepair of projections 34 eb and 34 ea touch to ends of the fixing pieces48S1 and 48S2 and the receptacle 20 and the connector plug 34 arepressed in the direction indicated by an arrow in FIG. 16C by theelastic force of the pressing pieces 46A and 46B. At that time, sincethe pair of projections 34 eb and 34 ea pressed by the elastic force ofthe pressing pieces 46A and 46B touch to the fixing pieces 48S1 and48S2, the separation of front ends of wires of the optical fibers 32from the micro-lens 22L is avoidable even if any tension is applied tothe optical fibers 32.

Also, since the micro-lens 22L of the receptacle 20 is pressed a contactend of the wire of the optical fibers 32 in the connecting portion ofthe connector plug 34 by a reaction force in accordance with thedisplacement of the pressing pieces 46A and 46B, a predetermined axialforce operates in the direction indicated by an arrow in FIG. 5. Forexample, it is necessary that the axial force of about 50 g is appliedto a single wire of one optical fiber 32 and maintained thereafter. Whenthe optical fibers 32 are constituted by a number of individual wires,for example, 20 ends, the axial force of 50 g×20 ends=1000 g=1 kg isnecessary.

In this regard, in the above-mentioned first and second embodiments, noferrule is used as shown in FIG. 5. However, the present inventionshould not be limited thereto but may, of course, be applied to aconnector plug provided with a ferrule as generally seen in the ordinaryoptical connectors. In such a case, an end surface of the optical fibermay coincide with that of the ferrule.

FIGS. 17 and 18 illustrate part of an optical connector provided with areleasable locking mechanism for an optical connector according to athird embodiment of the present invention.

The slant 30Rs of the locking nib 30Ra in the lock release button 30Rand the slant 30Ls of the locking nib 30La in the lock releasing button30L formed generally in a triangular shape in the embodiment shown inFIG. 2 are formed opposite to the slants 12 ns of the locking nibreceiving portion 12 nb and the slant 12 ns of the locking nib receivingportion 12 na in the locking mechanism fixing portion 12, respectively.In this embodiment, however, a slant 30′Ras of a locking pin 30′Ra in alock releasing button 30′R and a slant 30′Las of a locking pin 30′La ina lock releasing button 30′L formed in a generally cylindrical shape areformed opposite to a locking hole 12′Hb and a locking hole 12′Ha in thelocking mechanism fixing portion 12′, respectively.

At an end opposed to the receptacle 20 in the installation table 10, alocking mechanism fixing portion 12′ consisting of a locking mechanismfixing walls 12′WR and 12′WL is fixed. In this regard, while the lockingmechanism fixing portion 12′ is formed separately from the installationtable 10 according to this embodiment, this is not limitative, but thelocking mechanism fixing portion 12′ may be formed integral with theinstallation table 10, for example.

As shown in FIG. 17, the locking mechanism fixing wall 12′WR and thelocking mechanism fixing wall 12′WL are formed opposite to each otheracross a communication path 12′A.

On a wall surface of the locking mechanism fixing portion 12′WR opposedto the communication path 12′A, a recess 12′wd is formed. In this recess12′wd, a projection provided at a rear end of the connector plug 34described later is inserted at a gap between the both when the connectorplug 34 is connected. Also, on an end surface 12′wb of the lockingmechanism fixing portion 12′WR opposed to the receptacle 20, a lockinghole 12′Ha having a circular cross-section constituting part of alocking mechanism/unlocking mechanism described later is formed.

On a wall surface of the locking mechanism fixing wall 12′WL opposed tothe communication path 12′A, a recess 12′wc is formed. In this recess12′wc, a projection provided at a rear end of the connector plug 34described above is inserted between the both when the connector plug 34is connected. Also, on an end surface 12′wa in the locking mechanismfixing wall 12′WL as a position-restricting surface opposed to thereceptacle 20, a hole 12′Hb having a circular cross-section constitutingpart of a locking mechanism/unlocking mechanism described later isformed.

On the bottom of the communication path 12A, grooves 12′ga and 12′gbinto which are inserted the projections 34 pb of the connector plug 34,respectively, are formed generally parallel to each other. Depths of thegrooves 12′ga and 12′gb (see FIG. 18) are equal to each other, having adimension capable of completely accommodating the projection 34 pb.

As shown in FIG. 19, at an end opposed to the locking mechanism fixingwall 12′WR in a wall forming a button accommodation portion 20RR and ona side vertical to this end, an opening from which are projected thelocking pin 30Ra of the lock releasing button 30′R and the operatingpart thereof is formed. Also, at an end opposed to the locking mechanismfixing wall 12′WL in a wall forming a button accommodation portion 20′RLand on a side vertical to this end, an opening from which are projectedthe locking pin 30′La of the lock releasing button 30′L and theoperating part thereof is formed.

The lock releasing button 30′R is disposed within the buttonaccommodation portion 20RR to be reciprocable in the direction verticalto the axis of the shaft 14; i.e., along the side surface of theinstallation table 10. A coil spring 31′ is arranged as a first biasingmember for biasing the lock releasing button 30′R, between the end ofthe lock releasing button 30′R and the inner periphery of the buttonaccommodation portion 20RR. The lock releasing button 30′R has a stepengageable with the periphery of the opening from which projects theoperating part thereof. By the engagement of the step disposed in thebutton accommodation portion 20RR with the periphery of the opening, theremoval of the lock releasing button 30R is restricted.

As shown in FIG. 1, the slant 30′Ras of the locking pin 30′Ra of thelock releasing button 30′R is formed opposite to the above-mentionedlocking hole 12′Ha.

The lock releasing button 30′L is arranged in the button accommodationportion 20RL to be reciprocable in the direction vertical to the axis ofthe shaft 14; i.e., along the side surface of the installation table 10.As shown in FIG. 19, a coil spring 31′ is disposed between an end of thelock releasing button 30′L and the inner periphery of the buttonaccommodation portion 20RL, for biasing the lock releasing button 30′L.The lock releasing button 30′L has a step engageable with the peripheryof the opening through which is projected an operating part thereof. Bythe engagement of the step disposed in the button accommodation portion20RL with the periphery of the opening, the removal of the lockreleasing button 30′L is restricted.

The slant 30′Las of the locking pin 30′La of the lock releasing button30′L is formed while being opposed to the above-mentioned locking hole12′Hb.

Accordingly, the locking/unlocking mechanism for selectively locking orunlocking the receptacle 20 connected with the connector plug 34relative to the installation table 10 and the locking mechanism fixingportion 12 includes the locking pin 30′Ra of the lock releasing button30′R and the locking pin 30′La of the lock releasing button 30′L; thelocking holes 12′Ha and 12′Hb; and the coil spring 31′.

In such a structure, when the receptacle 20 mounted with the connectorplug 34 is in the locked state relative to the locking mechanism fixingportion 12′, in the initial position illustrated in FIG. 20A, the end ofthe shaft 14 is located at one end of the hole 10 a and the movable end16B of the leaf spring 16 does not yet start its movement.

Next, as shown in FIG. 20B, when the receptacle 20 is made to furtherrotate against the biasing force of the leaf spring 16, the pair ofprojections 34 eb and 34 ea formed opposed to the outer periphery of theconnector plug 34 touch to the end surfaces 12′wb and 12′wa of thelocking mechanism fixing portion 12′.

Subsequently, when the receptacle 20 is further pressed and made torotate against the biasing force of the leaf spring 16, as shown in FIG.20C, the projections 34 eb and 34 ea are displaced downward whilesliding on the end surface 12′wb and 12′wa of the locking mechanismfixing portion 12′. Since the coupling portions 20B and 20C of thereceptacle 20 as well as the connector plug 34 are pressed against thebiasing force of the leaf spring 16 at that time, the shaft 14 is apartfrom one end of the hole 10 a and displaced toward the other end thereofin the direction as indicated by an arrow. The movable end 16B of theleaf spring 16 is also displaced in the direction indicated by an arrowin FIG. 20C. At that time, the locking pins 30′Ra and 30′La are pressedagainst the biasing force of the coil spring 31′ while sliding theslants thereof.

And as shown FIG. 20D, when the receptacle 20 is in the locked staterelative to the locking mechanism fixing portion 12′, the shaft 14touches to the other end of the hole 10 a against the biasing force ofthe leaf spring 16. At that time, the locking pin 30′Ra and 30′La arepushed into the locking holes 12′Ha and 12′Hb, respectively, by therestoring force of the coil spring 31′ and fit therewith.

Also, the pair of projections 34 eb and 34 ea touches to the endsurfaces 12′wb and 12′wa of the locking mechanism fixing portion 12′,and the connector plug 34 is pressed in a stable state via thereceptacle 20 in the direction indicated by an arrow in FIG. 20D by thebiasing force of the leaf spring 16. Thereby, the same operation andeffect as those in the above-mentioned embodiment are obtainable.

FIGS. 21 and 22 illustrate parts of the appearance of an opticalconnector, respectively, provided with a fourth embodiment of areleasable locking mechanism according to the present invention.

While the lock releasing buttons 30R and 30L are provided in thereceptacle 20, and the locking nib receiving portions 12 nb and 12 naare provided in the locking mechanism fixing portion 12 opposite to eachother, lock releasing buttons 60L and 60R are provided in a lockingmechanism fixing portion 52, and locking nib receiving portions 50 naand 50 nb are provided in a receptacle 50 opposite to each other.

In FIG. 21, at an end of the installation table 10, a locking mechanismfixing portion 52 consisting of locking mechanism fixing walls 52WR and52WL is fixed. Note, while the locking mechanism fixing portion 52 isformed separately from the installation table 10 in this embodiment,this is not limitative but the locking mechanism fixing portion 52 maybe formed integral with the installation table 10.

The locking mechanism fixing wall 52WR and the locking mechanism fixingwall 52WL are formed opposite to each other while intervening with thecommunication path 52A between the both. On the wall surface of thelocking mechanism fixing wall 52WR opposite to the communication path52A, a recess 52 wd is formed. In the recess 52 wd, a projection at arear end of the connector plug 34 described later is inserted at apredetermined gap between the both when the connector plug 34 isconnected. Also, on an end surface 52 wb as a position-restrictionsurface in the locking mechanism fixing wall 52WR opposed to thereceptacle 50, a button accommodation portion 52RR is formed.

On the wall surface opposite to the communication path 52A, a recess 52wc is formed. When the connector plug 34 is connected, a projectionopposed to the projection at the rear end of the above-mentionedconnector plug 34 is inserted into the recess 52 wc with a predeterminedgap. Also, on an end surface 52 wa as a position-restriction surface inthe locking mechanism fixing wall 52WL opposed to the receptacle 50, abutton accommodation portion 52RL is formed.

At an end of a wall forming the button accommodation portion 52RRopposed to the locking mechanism fixing portion 52WR and on a side ofthe end, an opening is formed, from which are projected a locking nib60Ra of a lock releasing button 60R and an actuating part thereof. Also,at an end of a wall forming the button accommodation portion 52RLopposed to the locking mechanism fixing portion 52WL and on a side ofthe end, an opening is formed, from which are projected a locking nib60La of a lock releasing button 60L and an actuating part thereof.

The lock releasing button 60R is disposed in the button accommodationportion 52RR along an axis of the shaft 14, that is, to be reciprocablegenerally perpendicular to a side of the installation table 10. Betweena recess (not shown) at an end of the lock releasing button 60R and theinner periphery of the button accommodation portion 52RR, a coil spring61 is disposed as a first biasing member for biasing the lock releasingbutton 60R. The lock releasing button 60R has a step engageable with theperiphery of the opening from which is projected the actuating partthereof. By the engagement of a step arranged within the buttonaccommodation portion 52RR with the periphery of the opening, theremoval of the lock releasing button 60R and the predetermineddisplacement thereof are restricted.

As shown in FIG. 23, a slant 60Rs of the locking nib 60Ra in the lockreleasing button 60R having a generally triangular prism shape is formedopposite to the slant 50 ns of the locking nib receiving portion 50 nbdescribed later. Also, on one of other two sides intersecting with theslant 60Rs, an engagement surface 60Rt is formed, which is engaged witha retaining surface contiguous to the slant 50 ns of the locking nibreceiving portion 50 ns, when the receptacle 50 is in a locked state.

The lock releasing button 60L is disposed in the button accommodationportion 52RL along an axis of the shaft 14, that is, to be reciprocablegenerally perpendicular to a side of the installation table 10. Betweena recess 60Lr at an end of the lock releasing button 60L and the innerperiphery of the button accommodation portion 52RL, a coil spring 61 isdisposed as shown in FIG. 23 for biasing the lock releasing button 60L.The lock releasing button 60L has a step engageable with the peripheryof the opening from which is projected the actuating part thereof. Bythe engagement of a step arranged within the button accommodationportion 52RL with the periphery of the opening, the removal of the lockreleasing button 60L and the predetermined displacement thereof arerestricted.

A slant 60Ls of the locking nib 60La in the lock releasing button 60Lhaving a generally triangular prism shape is formed opposite to theslant 50 ns of the locking nib receiving portion 50 nb described later.Also, on one of other two sides intersecting with the slant 60Ls, anengagement surface 60Rt is formed, which is engaged with a retainingsurface contiguous to the slant 50 ns of the locking nib receivingportion 50 ns when the receptacle 50 is in a locked state.

On the bottom of the communication path 52A, as shown in FIG. 23,grooves 52 ga and 52 gb into which are inserted the projections 34 pb,respectively, are formed generally parallel to each other. Depths of thegrooves 52 ga and 52 gb are of the same dimension capable of completelyaccommodating the projections 34 pb.

As illustrated in FIGS. 21 and 22, the receptacle 50 mainly includes arotary table 50F having coupling portions 20B and 20C coupled to themiddle portion of the shaft 14, and an end cap 50E covering one end ofthe rotary table 50F.

The covering portions 50B and 50C formed on the lower surface of therotary table 50F opposite to each other at a predetermined distance haveholes 50 b and 50 d into which is inserted the middle portion of theshaft 14, respectively. Thereby, the receptacle 50 is held by the rotarytable 50F and the shaft 14 to be rotatable relative to the installationtable 10.

The rotary table 50F has a connector plug accommodation portion 50A fordetachably accommodating and supporting the tubular portion 34CL of theconnector plug 34 as a connecting portion. A structure of the connectorplug accommodation portion 50A is the same as that of theabove-mentioned connector plug accommodation portion 20A. Also, astructure of the end cap 50E is the same as that of the above-mentionedend cap 20E.

On opposite end surfaces of the connector plug accommodation portion50A, recesses 50 we and 50 wd are formed, respectively.

On the wall surface forming the recess 50 we, the locking nib receivingportion 50 nb constituting part of the locking mechanism/unlockingmechanism is formed. For example, the hook-shaped locking nib receivingportion 50 nb is formed to be vertical to the outer side surface thereofand project into the recess 50 we. As shown in FIG. 22, a slant 50 nsfor guiding the above-mentioned locking nib 60Ra is formed in thelocking nib receiving portion 50 nb. A retaining surface formed abovethe locking nib receiving portion 50 nb contiguous to the slant 50 ns isgenerally vertical to the outer side surface thereof.

On the wall surface forming the recess 50 wd, the locking nib receivingportion 50 na constituting part of the locking mechanism/unlockingmechanism is formed. The locking nib receiving portion 50 na is formedto be vertical to the outer side surface thereof and project into therecess 50 wd. A slant 50 ns for guiding the above-mentioned locking nib60La is formed in the locking nib receiving portion 50 na. A retainingsurface formed above the locking nib receiving portion 50 na contiguousto the slant 50 ns is generally vertical to the outer side surfacethereof.

In such a structure, when the receptacle 50 mounted with the connectorplug 34 is locked to the locking mechanism fixing portion 52, first, thereceptacle 50 is made to rotate against the biasing force of the leafspring 16 toward the end surfaces 52 wa and 52 wb of the lockingmechanism fixing portion 52.

Next, when the receptacle 50 is further made to rotate, the slants 60Rsand 60Ls of the locking nib 60Ra slide on the slants 50 ns of lockingnib receiving portions 50 na and 50 nb, respectively, whereby thelocking nib 60Ra and the locking nib 60La are moved in the directionclose to each other against the biasing force of the coil spring 61.

Subsequently, when the receptacle 50 is further pressed and made torotate, whereby the locking nib 60Ra and the locking nib 60La aredisplaced to the predetermined maximum extent, the slant 50 ns ispressed downward. Thereby, the engagement surfaces 60Rt and 60Lt of thelocking nib 60Ra and the locking nib 60La are engaged with the retainingsurfaces of the locking nib receiving portions 50 na and 50 nb,respectively, resulting in the locked state. At that time, since twoprojections 34 pb of the connector plug 34 are inserted into the grooves52 ga and 52 gb, the outer surface of the connector plug 34 touches tothe bottom surface of the communication path 52A.

Accordingly, the displacement of the receptacle 50 mounted with theconnector plug 34 is restricted in any direction in the above-mentionedlocked state.

On the other hand, when the receptacle mounted with the connector plug34 is changed from the locked state to the unlocked state relative tothe locking mechanism fixing portion 52, first, the actuating part ofthe lock releasing button 60R and the actuating part of the lockreleasing button 60L are pressed against the biasing force of the coilspring 61 in the mutually approaching direction. Thereby, the engagementsurfaces 60Rt and 60Lt of the locking nib 60Ra and the locking nib 60Laare disengaged from the retaining surfaces of the locking nib receivingportions 50 na and 50 nb, resulting in the unlocked state.

Thereafter, in a similar manner as in the above-mentioned embodiments,the receptacle 50 mounted with the connector plug 34 returns to theinitial position by the biasing force of the leaf spring 16.

1-13. (canceled)
 14. A releasable locking mechanism for an opticalconnector comprising: a lock releasing button having a lock-fixingportion and movably disposed in either one of a receptacle or a basebeing disposed opposite to said receptacle, said receptacle having aconnector plug accommodation portion for detachably accommodating aconnector plug being connected to optical fibers to form a transmissionpath for photoelectric converted signals; a locking nib receivingportion formed opposite to said lock releasing button in either one ofsaid receptacle or said base, for selectively fixing said lock-fixingportion to result in a locked state of said receptacle and saidconnector plug relative to said base; a first biasing member for biasinga locking nib of said lock releasing button in direction that fix it tosaid locking nib receiving portion; a position restricting surface fortouching and holding an end of said connector plug mounted to saidconnector plug accommodation portion in said locked state, and a secondbiasing member for biasing said receptacle in the axial direction ofsaid optical fibers when an end of said connector plug mounted to saidconnector plug accommodation portion is retained by said positionrestricting surface.
 15. A releasable locking mechanism for an opticalconnector comprising: a lock releasing button having a lock-fixingportion and movably disposed in either one of a receptacle or a basedisposed opposite to said receptacle, said receptacle having a connectorplug accommodation portion for detachably accommodating a connector plugbeing connected to optical fibers to form a transmission path forphotoelectric converted signals; a locking nib receiving portion formedopposite to said lock releasing button in either one of said receptacleor said base, for selectively fixing said lock-fixing portion to resultin a locked state of said receptacle and said connector plug relative tosaid base, a first biasing member for biasing a locking nib of said lockreleasing button in direction that fix it to said locking nib receivingportion; a position restricting member disposed in said base, forrestricting the position of a predetermined end of said connector plugmounted to said connector plug accommodation portion when said connectorplug mounted to said connector plug accommodation portion is in saidlocked state, and a second biasing member for biasing ends of saidconnector plug and said optical fibers toward the bottom of saidconnector plug accommodation portion in the axial direction of saidoptical fibers when the position of said end of said connector plug isrestricted by said position restricting member.
 16. The releasablelocking mechanism for an optical connector as claimed in claim 14,wherein said receptacle is rotational movably supported relative to saidbase.
 17. The releasable locking mechanism for an optical connector asclaimed in claim 14, wherein said second biasing member is an elasticmember for directly or indirectly pressing a shaft rotatably supportingsaid receptacle.
 18. The releasable locking mechanism for an opticalconnector as claimed in claim 17, wherein said elastic member is a leafspring made of metal or heat-resistant rubber.
 19. The releasablelocking mechanism for an optical connector as claimed in claim 15,wherein said second biasing member is a leaf spring having a pressingpart in contact with an end of said connector plug and biasing the same.20. The releasable locking mechanism for an optical connector as claimedin claim 14, wherein connecting end surfaces of said optical fiberstouch to the bottom of said connector plug at a uniform pressure, whenthe end of said connector plug mounted to said connector plugaccommodation portion touches to a position restricting surface and isheld there.
 21. The releasable locking mechanism for an opticalconnector as claimed in claim 19, wherein when a movable end of saidleaf spring is supported by said shaft movably held in an ellipsoidalhole provided in said base, said connector plug is mounted in saidconnector plug accommodation portion as said receptacle is apart fromsaid base, and said connecting ends of said optical fibers touch to thebottom of said connector plug accommodation portion at a uniformpressure based on the recovery force in accordance with the elasticdisplacements of the movable end of said leaf spring when saidreceptacle becomes horizontal relative to the surface of said base andthe end of said connector plug mounted to said connector plugaccommodation portion touches to a position restricting member formed onan end surface of said base and is held there.
 22. The releasablelocking mechanism for an optical connector as claimed in claim 19,wherein said lock releasing button and locking nib receiving portion areprovided at two places, respectively.
 23. The releasable lockingmechanism for an optical connector as claimed in claim 20, wherein saidreceptacle is separable from said base and said connector plug isdetachable from said connector plug accommodation portion when saidlocking nib is released from said locking nib receiving portion bypressing said lock releasing button against the biasing force of saidfirst biasing member.
 24. The releasable locking mechanism for anoptical connector as claimed in claim 22, wherein the bottom of saidconnector plug accommodation portion in said receptacle is constitutedby a transparent thin plate member provided with a micro-lens touchingat a predetermined pressure to the end surface of said optical fiberprojected through a micro-hole formed in said connector plug, wherebythe output of optical signals from said optical fiber to outside or theinput of optical signals from outside to said optical fiber is possible.25. The releasable locking mechanism for an optical connector as claimedin claim 23, wherein said connector plug is provided with a ferrule intowhich are embedded said optical fibers, wherein the end surfaces of saidoptical fibers coincide with the end surface of said ferrule.
 26. Thereleasable locking mechanism for an optical connector as claimed inclaim 14, wherein said base has a means for dissipating heat.
 27. Thereleasable locking mechanism for an optical connector as claimed inclaim 15, wherein said receptacle is rotational movably supportedrelative to said base.
 28. The releasable locking mechanism for anoptical connector as claimed in claim 15, wherein said base has a meansfor dissipating heat.